From: Peter Seebach <peter.seebach@windriver.com>
To: Peter Zijlstra <peterz@infradead.org>
Cc: Ingo Molnar <mingo@elte.hu>,
Arnaldo Carvalho de Melo <acme@redhat.com>,
Anton Blanchard <anton@samba.org>, <paulus@samba.org>,
<dsahern@gmail.com>, <fweisbec@gmail.com>,
<yanmin_zhang@linux.intel.com>, <emunson@mgebm.net>,
<linux-kernel@vger.kernel.org>
Subject: Re: [PATCH] perf: Incorrect use of snprintf results in SEGV
Date: Wed, 7 Mar 2012 15:28:48 -0600 [thread overview]
Message-ID: <20120307152848.562c72f2@wrlaptop> (raw)
In-Reply-To: <1331153964.11248.362.camel@twins>
On Wed, 7 Mar 2012 21:59:24 +0100
Peter Zijlstra <peterz@infradead.org> wrote:
> On Wed, 2012-03-07 at 21:37 +0100, Ingo Molnar wrote:
> > size_needed = snprintf_size(...);
>
> This would require 3 passes over the fmt+args, first to find the
> allocated size is insufficient, 2nd to compute the size, 3rd to fill
> buffer.
>
> Whereas with the current "creative" API only 2 passes are needed.
>
> I can imagine that back in the day of small memory and small CPU this
> was deemed important enough.
It occurs to me that I have seen this discussion, or a variant, before:
http://coding.derkeiler.com/Archive/C_CPP/comp.lang.c/2004-11/2332.html
In which people discuss the possible alternative return values at some
length.
-s
--
Listen, get this. Nobody with a good compiler needs to be justified.
next prev parent reply other threads:[~2012-03-07 21:29 UTC|newest]
Thread overview: 17+ messages / expand[flat|nested] mbox.gz Atom feed top
2012-03-07 0:42 [PATCH] perf: Incorrect use of snprintf results in SEGV Anton Blanchard
2012-03-07 0:49 ` Peter Seebach
2012-03-07 1:09 ` Arnaldo Carvalho de Melo
2012-03-07 1:29 ` Peter Seebach
2012-03-07 18:44 ` Nick Bowler
2012-03-07 20:24 ` Peter Seebach
2012-03-07 20:37 ` Ingo Molnar
2012-03-07 20:59 ` Peter Zijlstra
2012-03-07 21:28 ` Peter Seebach [this message]
2012-03-08 7:34 ` Ingo Molnar
2012-03-08 8:51 ` Peter Seebach
2012-03-07 21:19 ` Peter Seebach
2012-03-08 0:58 ` Arnaldo Carvalho de Melo
2012-03-08 7:48 ` Ingo Molnar
2012-03-08 7:52 ` Ingo Molnar
2012-03-09 19:00 ` Peter Seebach
2012-03-14 19:59 ` [tip:perf/urgent] perf tools: " tip-bot for Anton Blanchard
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